General James Mattis served more than 40 years in the Marines, much of it commanding troops in battle. But he almost didn't make it to boot camp. In this extensive two-part interview, he talks with David Martin about his years in Afghanistan and Iraq, following orders from the Bush administration that he characterized as incoherent, and serving as Secretary of Defense under President Trump. He also talks about his distaste for his colorful nickname, "Mad Dog," and shows off his library of 7,000 books, to which he's added another – his own, titled "Call Sign Chaos: Learning to Lead."